Short answers, pulled from the story.
In 1982, musicologist Franco Fabbri defined a musical genre as a set of musical events governed by socially accepted rules rather than a fixed box. This framework suggests that the existence of a genre relies on the collective agreement of its listeners and creators. The definition transformed musicology by revealing that genre is a dynamic social contract.
Musicologist Philip Tagg developed an axiomatic triangle consisting of folk, art, and popular musics to distinguish them. Folk music is classified as music orally passed from one generation to another, while art music is primarily a written tradition preserved in notation. Popular music differs from art music through its mass distribution strategy and non-written distribution modes.
Country music, also known as country and western, originated in the southern United States in the early 1920s. This genre emerged from the combination of European folk music brought by British immigrants with the blues and spirituals of African Americans. The fusion created a separate musical form that became a defining element of American culture.
Vincenzo Caporaletti developed Audiotactile Music Theory to categorize music in three branches: written music, oral music, and Audiotactile music. This framework defines each branch by the formative medium with which a music is created. The theory explains how sound recording technologies created a third branch of music in the 20th century.
Glenn McDonald created an algorithmically generated scatter-plot of the musical genre-space based on data tracked for 5,315 genre-shaped distinctions. This data-driven approach maps the relationships between genres in a system called Every Noise at Once. The project reveals hidden connections between genres that human listeners might miss.